The structure of the song is unconventional in that it has nothing resembling a typical chorus. Instead, the song progresses from the intro into a mid-tempo section which alternates between two verses. The first verse begins with the line "Karma police", and the other begins with the line "This is what you'll get". After this section cycles through twice, the song switches into a second section which is based around the line "For a minute there, I lost myself". During this section of the song, Yorke's voice is put through an echo effect and a sliding melodic figure serves as a counterpoint to his vocals.[9]

"This is really schizophrenic, isn't it? There's that huge personality change halfway through. Wait until you see the video! We're making the whole LP into a film, commissioning it song by song." – Thom Yorke[10]

Radiohead members used to tell one another that they would call "the karma police" on them if they did something bad; a joke incorporated into the lyrics and title of the song.[11] Yorke explained that the song was about stress and "having people looking at you in that certain [malicious] way, I can't handle it anymore".[12] In 2006, he explained to The Independent: "It's for someone who has to work for a large company. This is a song against bosses. Fuck the middle management!"[8] Yorke and Jonny Greenwood emphasised in interviews that the song had a humorous bent. "[It's] not entirely serious," said the former. "I hope people will realize that."[12] The line "He buzzes like a fridge/He's like a detuned radio" refers to distracting, metaphorical background noise that Yorke calls "fridge buzz" – a concept that, he said, is one of the primary themes of OK Computer.[13] "Karma Police" also shares themes of insanity and dissatisfaction with capitalism.[14]

In the last minute of the song, Ed O'Brien plays a few guitar notes that are distorted by overloading an AMS rackmount digital delay unit. The song ends with the distorted notes 'melting' as he turns the delay rate knob down to a low frequency.[15]

"Karma Police" was released as the second single from OK Computer on 25 August 1997. The single was released in two versions. The single peaked at number eight on the UK Singles Chart.[16] In late March 2010, almost thirteen years after its initial single release, the song went to number fifteen on the Danish Singles Chart.[17] In a song review, AllMusic referred to Karma Police as "haunting, mystifying, and exquisite", labelling it "one of the cornerstones of one of the greatest albums of the '90s."[9]

The video starts with the camera, an unseen driver, looking at the empty back seat of a 1976 Chrysler New Yorker at night. Footsteps are then heard walking to the car, the back door opens and someone gets in. The 'driver' then begins driving. For 35 seconds, it shows nothing but a road through grass illuminated by headlights, with insects visible around the windscreen. In time for the chorus the view shifts to the back seat, where Thom Yorke now sits, almost mumbling his lyrics. The view yet again moves to a man, running for his life. The view again switches to Yorke, now slouching drowsily against the back of the front seat, barely lipsyncing any longer. The camera swivels and the man appears again, closer this time. For the first time another perspective reveals the outside of the car. The fleeing person sharpens and is revealed to be a large man with a frightened look. He stops out of breath, fearing the worst. He collapses to his knees, giving up. The car comes to a stop before him, then reverses slightly, as if for a 'run up', and this reveals it to be leaking fuel. The man realises the car has a petrol leak and puts his hands behind his back as if in resignation, then takes matches from his pocket, desperately trying to catch a flame, manages to, and throws it down. The perspective shifts to the car's interior. The car suddenly reverses, away from the man, a path of fire now blazes back towards the car. The car slowly catches fire, and the camera/driver finally turns frantically to the back seat and robotically swivels back and forth, only to find that Yorke is no longer there. The car is completely engulfed in flames.